Chuck



`Patented Nov. 29, 1927.

Unirse STATES PATENT OFFICE.

l CHARLES N. ELLRCH, 0F SOUTHINGTON, CONNECTICUT, ASSGNOR TO THE PECK STOW c 'WLCOX C0., OF SOUTI-IINGTON, CONNECTICUT, A CORPORATION.

CHUCK.

Application filed September 4, 1926.

Fig. 1 is a broken view in side elevation of a bit-brace with my improved chuck applied thereto.

Fig. 2 is a view of my improved chuck in longitudinal, central section.

23 is a transverse, sectional view on the line 3 3 of Eig. 2.

Fig. 4 is a detached view of the shank turned at a right angle to the position in which it is shown in Fig. 2, and showing the jaws in place therein.

F ig. 5 is a detached view, partly in side elevation and partly in section, of the inner cone. A

Fig. 6 is a corresponding view of the outer cone.

My invention relates to an improved toolholding chuck designed primarily for bitbraces, but not so limited in its application, the object being to provide an eflicient and durable chuck, composed of few parts, and constructed with particular reference to insuring the uniform movement of the two jaws in a right line, whereby their uniform grip on atool-shank is insured, and whereby the max'mum amount of gripping action is secured with the minimum amount of exertion by the user.

With these objects in view, my invention consists in a chuck having two correspondingly inclined jaw-operating surfaces movable with respect to the shank of the chuck for sliding coaction with 'the inner and outer ends of the respective jaws.

My invention further consists in a chuck characterized as above and having certain details of construction and combinations of parts as will be hereinafter described and particularly pointed out in the claims. A

For the illustration of my invention, I have shown it as applied to a bit-brace. though, as already indicated, its use is not so limited.

As herein shown, theshank 10 enters a head 11 secured to a crank 12 having a handle 13, these parts being of usual construe-- tion. The shank is formed with threads 14 offsetting from its body and providing for the application to it of the internally-thread- -ed cap-member 15 forming a part of the chuck-body. The outer end of the said capinember is externally-threaded as at 16 for the application to it of the internally-threaded inner end of the cup-member 17 of the chuCl-.hody The said inner end of the cup- Serial No. 133,799.

member abuts against a flange 18 near the outer end of the cap-member, the two members being secured together against relative rotation by means of a screw 19. rIAhe outer end of the cup-member is inwardly-turned to form an outer race 2O for a series of antifriction balls 21, the inner race therefor being formed by an outwardly-projecting flange 22 at the inner end of an outer, awoperating cone 23, the flanged inner end of which is located within thelower end of the cup-member 17. The cone 28 is'formed with an internal, conical surface 24 which coacts with the conically-contoured outer ends 25 of a pair of complementary jaws 26. rlhe inner ends of the said jaws extend-into a transverse-slot 27 in the outer end of the shank 10, where they are conically contoured as at 28 for co-action with a conical surface 29 formed within an inner, jaw-operating cone 30 located entirely within the cup-member 17 and at its outer end riding upon the inner end of the outer, atv-operating cone 23.

The jaw-operating surfaces 24 and 29 whether conical or otherwise, slope in the same direction, whereby the inner and outer ends of the jaws are synchronously moved inward or outward to expand or contract the tool-receiving space between the jaws, the said surfaces 24 and 29 having sliding coaction with the adjacent bevels of the'jaws,

which are thus maintained in parallelism.

For normally maintaining the bevellcd surfaces at the inner and outer ends of the jaws' in contact with the co-acting, conical surfaces of the inner and outer jaw-operating cones, I employ a jaw-operatingspring 31 formed midway of its ends with a positioning-loop 32, through which a pin 33, diametrically mounted near the outer end of the shank, passes. The inner portion of this spring is located within a -narrowslot 34 leading out of the inner end of the slot 27 aforesaid. The respective arms of the said springs pass through inclined clearance-bores 35 in the inner ends of therespective jaws, and at their extreme ends they are bent to form hooks 36 for preventing the appreciable outward movement of the jaws with respect to the shank.

By providing the chuck with an outer and an inner jaw-operating cone for co-action with conically-contoured surfaces at the respective ends of the jaws, the same are uniformly crowded upon the shank, so as to member grip the same uniformly and with power, while the insertion of ball-bearings between the cup-member of the body and the outer, jaw-operating cone .enables the respective ends of the jaws to be forced against the shank of the tool with great force and with the minimum of effort. By making the inner and outer cones independent of each other, manufacture is facilitated, and they are permitted to relatively rotate according` to the Conditions of use, but they might be made in one piece, if desired.

I claim:

' 1. In a chuck'the combination with an externally-threaded shank, of a body comprising a cap-member threaded upon the shank and a cup-member secured to the said cap-member, the latter 'having itsA ont-er end turned inwardly to form a ball-race, an outer jaw-operating cone bodily movable with respect tothe said shank and having,` its inner end extended into the said cupand overhanging the ball-race aforesaid, ball-bearings located between the said cup-member and the said. outer cone, an inner cone bodily movable with respect to said shank and located within the cupmember and bearing at its outer end upon the inner end of the outer cone, two complementary jaws each having parallel inner and outer cone-engaging surfaces respectively co-acting with the said inner cone and with the said outer con-e, and resilient means for yieldingly holding the jaws in their separated positions.

2. In achuck, the combination with an externally-threaded shank, of a body threaded thereupon, inner and outer cones carried by the'said body so as to be movable with respect to the said shank and each havingl a cerrespondingly-inclined jaw-operating surface, two complementary jaws having' sliding co-action at theirl inner 'ends with the said inclined surface of the inner cone and also having sliding co-action at their outer ends with the said inclined surface of the outer cone, and means for yieldingly holding' the jaws in their separated. positions and against the said jaw-operating surfaces.

3. In a chuck, the combination'with an extcrnally-threaded shank, of a body threaded thereupon,r inner and outer jaw-operating members carried by the said body as to be movable with respect to the said shank and each having a correspondingly-inclined j:iw-operating` surface, two complementary jaws 'having sliding co-action at their inner ends with the jaw-operating surface of thax said inner jaw-operating` member and also having sliding co-action at their outer ends with the jaw-operating surface of the said outer jaw-operating member, and means for yieldingly holding the jaws in their separated positions and against the said jawoperating surfaces.

4l. In a chuck, the vcoi'n'bination with an externally-threaden shank, of afbody comprising a cap-member threaded upon the said shank and a cup-member secured to the said cap-member, inner and outer jawoperating cones arriedby the said body to be movable with respect to the said shank and each having correspondingly-inclined jaw-operating surfaces, two complementary jaws having sliding co-aetion at their inner ends with the inclined surface of the said inner cone and also having sliding co-action at their outer ends with the inclined surface of the said outer cone, and means for holding the jaws in their separated positions and against the said inclined surfaces of the cones. A

5. In a chuck, the combination with an externally-threaded shank, of a body threaded upon said shank,v inner and outer jawoperating` cones carried by the said body s( as to be movable with respect to theV said shank and each having correspondingly-inclined jaw-operating surfaces, two comple.-

mentary jaws having slidingco-action at their innerends with the jaw-operating surface of the inner cone and also having` sliding` co-action at their out-er ends with the jaw-operating surface of the outer cone, a two-armed sprinO, and means for-'couplingI the saine with the shank'and with the respective jaws for limiting the endwise movement of the jaws with respect to the shank.

6. In a chuck, thel combination with an eXternally-threa'ded shank provided with a jaw-recei ring slot and with a spring-receiving` slot, of a body threaded upenthe said shank, inner and outer cones carried by the said body as to be movable with respect to the said shank and each having corresponningly-inclined jaw-operating` surfaces, two complementary jaws, the inner ends of which enter the said jaw-rect-iivingg` slot and the inner and outer ends of which have sliding co-action with .the jaw-oper.t :ing surfaces of theinner and outer cones respectively', ay spring entering' the spring-receiving; slot, and means for coupling the saine with the shank and with the jaws for movingthe latter outwardly and limiting' their eudwise movement lwith respect to the Shank.

vIn testimony whereof, 'l' havesigned this specification. Y

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